You can use ChemBuddy – CASC to calculate concentration and to mix solution.

To calculate concentration, you just need to entry substance from ChemBuddy database, and it will automatically show formula, molar mass. And you should fill the form such as mass (g), n (mol), V (mL), Sm (g), M (mol/L), % (w/w), mM (mmol/L), ppm (w/w), m (mol/kg), % (w/v), x, d (g/mL, g/L, kg/m3, /lb/ft3 or lb/gal); leave one of the form to calculate it.

To calculate mixture, you just need to entry sunstnce from ChemBuddy database, add 1^st solution such as concentrate (M (mol/L), mM (mmol/L), m (mol/kg), % w/w, ppm, % w/v, x, d (g/mL)); V (mL) and then Sm (g). Then, you need to add 2n solution such as concentrate (M (mol/L), mM (mmol/L), m (mol/kg), % w/w, ppm, % w/v, x, d (g/mL)); V (mL) and then Sm (g). Now you will mixed solution such as concentrate (M (mol/L), mM (mmol/L), m (mol/kg), % w/w, ppm, % w/v, x, d (g/mL)); V (mL) and then Sm (g).

From the help menu, you can see the example question and how this software can solve it, such as:

What is the molarity of the solution containing 11g of potassium dihydrogen phosphate in 100mL? What is the molality of the acetic acid solution with density of 1.0230 g/mL? What if the density is 1.0510 g/mL? What is the mole fraction of HCl if 100g of the solution contains 1 mole of HCl? What is the mass of HCl in 1 liter of this solution? Given a solution with a density of 1.132 g/mL containing 45% w/w water and the remainder being an organic compound with a molecular mass of 46 g/mol. What is the molar concentration of the organic compound in the solution? How to prepare 1.5 L of 0.1M sodium tetraborate solution? You have a 1M stock solution of TRIS buffer, a 10% stock solution of magnesium chloride and a bottle of crystalline sucrose. Use these reagents to make 600 ml of a solution containing 25 mM TRIS, 15 mM MgCl2 and 30% sucrose; What will be the molar concentration of sodium hydroxide if 100mL of 5% NaOH is mixed with 50g of 20% NaOH? How to dilute stock solution of sulfuric acid (98% w/w) to obtain 100 mL of 1M solution? Flexibility of CASC or three ways to find out how to prepare 100mL of 0.1M LiCl from a 0.78M solution of LiCl.  

In substances database, it has 327 items. In each item you can see its substance name, solved formula, solved molar mass, stock concentration, choose standard substance, use stock solution, choose no density table and choose no solid. The subsances are: 1,2 propylene glycol, acetic acid, acetic aldehyde, acetic aldehyde, acetone, acetonitrile, aluminum ammonium sulfate, aluminum bromide, aluminum chloride, aluminum nitrate, aluminum sulfate, ammonia, ammonium acetate, ammonium bromide, ammonium carbonate, ammonium chloride, ammonium dichromate, ammonium fluoride, ammonium formate, ammonium hydrogen malate, ammonium iodide, ammonium malate, ammonium nitrate, ammonium oxalate, ammonium perchlorate, ammonium peroxydisulfate, ammonium propionate, ammonium sulfate, ammonium thiocyanate, aniline hydrochloride, arsenic acid, barium acetate, barium bromide, barium chlorate, barium chloride, barium formate, barium iodide, barium malate, barium nitrate, barium propionate, beryllium chlorate, beryllium chloride, beryllium nitrate, beryllium sulfate, boric acid, cadmium bromide, cadmium chlorate, cadmium chloride, cadmium iodide, cadmium nitrate, cadmium sulfate, calcium acetate, calcium bromide, calcium chlorate, calcium chloride, calcium chromate, calcium formate, calcium hexacyanoferrate (II) , calcium iodide, calcium nitrate, calcium propionate, cerium (III) sulfate, cesium bromate, cesium bromide, cesium chlorate, cesium chloride, cesium iodate, cesium iodide, cesium nitrate, cesium sulfate, chloric acid, chloro(methylamino)acetic acid, chromium (III) bromide, chromium (III) chloride, chomium (III) nitrate, chromium (VI) oxide, citric acid, cobalt (II) acetate, cobalt (II) bromide, cobalt (II) chlorate, cobalt (II) chloride, cobalt (II) nitrate, cobalt (II) sulfate, cobalt (II) thiocyanate, copper (II) acetate, copper (II) chlorate, copper (II) chloride, copper (II) formate, copper (II) nitrate, copper (II) propionate, copper (II) sulfate, D-fructose, diethylamine hydrochloride, dimethylamine hydrochloride, EDTA, ethanol, ethylamine hydrochloride, ethylene glycol, formaldehyde, formic acid, glucose, glycerine, hexafluorosilicic acid, hydrazine, hydrazine dihydrochloride, hydrobromic acid, hydrochloric, hydrocyanic acid, hydrogen peroxide, hydroiodic acid, hydroxylamine, hydroxylamine hydrochloride, indium (III) bromide, iodic acid, iron (II) bromide, iron (II) chloride, iron (II)nitrate, iron (II) sulfate, iron (III) ammonium sulfate, iron (III) chloride, iron (III) nitrate, iron (III) sulfate, lactose, lanthanum nitrate, lead (II) acetate, lead (II) chlorate, lead (II) nitrate, lithium acetate, lithium bromide, lithium chlorate, lithium chloride, lithium chromate, lithium dichromate, lithium formate, lithium hydrogen malate, lithium hydroxide, lithium iodate, lithium iodide, lithium malate, lithium nitrate, lithium sulfate, lithium thiocyanate, magesium chromate, magnesium acetate, magnesium bromate, magnesium bromide, magnesium chlorate, magnesium chloride, magnesium formate, magnesium iodide, magnesium nitrate, magnesium sulfate, maltose, manganese (II) acetate, Manganese (II) bromide, manganese (II) chloride, manganese (II) nitrate, manganese (II) sulfate, mercury (II) chlorate, mercury (II) chloride, mercury (II) cyanide, methanol, nickel (II) bromide, nickel (II) chlorate, nickel (II) chloride, nickel (II) nitrate, nickel (II) sulfate, nitric acid, oxalic acid, perchloric acid, periodic acid, peroxydisulfuric acid, phosphoric acid, potassium acetate, potassiumazide, potassium bromate, potassium bromide, potassium carbonate, potassium chlorate, potassium chloride, potassium chromate, potassium citrate, potassium cyanate, potassium cyanide, potassium dichromate, potassium dihydrogen carbonate, potassium hydrogen malate, potassium hydrogen oxalate, potassium hydrogen phthalate, potassium hydrogen sulfate, potassium hydrogen sulfide, potassium hydroxide, potassium iodate, potassium iodide, potassium malate, potassium metasilicate, potassium metavanadate, potassium molybdate, potassium nitrate, potassium nitrite, potassium oxalate, potassium perchlorate, potassium permanganate, potassium phosphate, potassium propionate, potassium pyrosulfate, potassium pyrosulfate, potassium selenate, potassium sodium tartrate, potassium sulfate, potassium sulfite, potassium tartrate, potassium tellurite, potassium tetrachloroplatinate (II) , potassium thiocyanate, potassium tungstate, propanol-1, propanol-2, rubidium bromate, rubidium bromide, rubidium chlorate, rubidium chloride, rubidium fluoride, rubidium hydroxide, rubidium iodate, rubidium iodide, rubidium nitrate, rubidium sulfate, rubidium tartrate, selenic acid, silver chlorate, silver fluoride, silver nitrate, sodium acetate, sodium arsenate, sodium azide, sodium benzoate, sodium bromate, sodium bromide, sodium carbonate, sodium chromate, sodium citrate, sodium dichromate, sodium dihydrogen arsenate, sodium dihydrogen phosphate, sodium fluoride, sodium formate, sodium fumarate, sodium glycerate, sodium glycolate, sodium hydrogen arsenate, sodium hydrogen carbonate, sodium hydrogen malate, sodium hydrogen phosphate, sodium hydrogen sulfate, sodium hydrogen sulfite, sodium hydrogen tartrate, sodium hydroxide, sodium iodide, sodium lactate, sodium malate, sodium maleate, sodium malonate, sodium metasilicate, sodium metavanadate, sodium molybdate, sodium nitrate, sodium nitrite, sodium oxalate, sodium perchlorate, sodium phosphate, sodium propionate, sodium pyrophosphate, sodium selenate, sodium stannate, sodium sulfate, sodium sulfide, sodium sulfite, sodium tartrate, sodium tetraborate, sodium thiocyanate, sodium thiosulfate, strontium acetate, strontium bromate, strontium bromide, strontium chlorate, strontium chloride, strontium formate, strontium hexacyanoferrate (II), strontium iodide, strontium nitrate, sucrose, sulfuric acid, sulfurous acid, tartaric acid, tellurous acid, tetraethylammonium chloride, tetramethylammonium chloride, tetrapropylammonium chloride, thalium (I) fluoride, thalium (I) nitrate, thalium (I) sulfate, thorium (IV) chloride, thorium (IV) nitrate, tin (II) chloride, tin (IV) chloride, trichloroacetic acid, triethylamine hydrochloride, TRIS, tungsten (VI) oxide, uranyl acetate, uranyl nitrate, urea, zinc acetate, zinc bromate, zinc bromide, zinc chlorate, zinc chloride, zinc iodide, zinc nitrate, zinc sulfate.

You can download this software from: http://www.chembuddy.com/files/CASCInstall.msi