Here is the full list of all 15 Just Find It achievements.
Find 10 Difference
Find 50 Difference
Finish 10 Difference Mode Levels
Finish 30 Difference Mode Levels
Complete Difference Mode
Complete All Swap Mode
Complete All Match Mode
Complete Detail Mode
Use Hint for the first time
Use Hint at least 10 times
Use Hint 30 times
Play a Difference Mode without using Hint
Play a Swap Mode without using Hint
Play a Match Mode without using Hint
Play a Detail Mode without using Hint