Tried them all...

…this is the one, hands down. I dont know all the units there are, but I havent found one this app doesnt know. I do have a thing about land measures, though, and the app is complete in that category, with niceties like township and sq rods. It has shoe and clothing sizes for men and women, and a lot of foreign measures I dont know.
ps, I train with kettlebells and this app knows пуд (pud or pood)!

Taijitu about Measures - Unit Converter, v2.3.4