From top: bamboo 竹, the image of an abacus 目 [= counting board], and two hands 廾 (twice this hand 屮 with the fingers 山 towards the top; simplified & combined)
Mnemonic
I use the bamboo abacus with both hands to calculate.
The app has many other functions, such as character selection according to difficulty, practice programs, handwriting recognition and success statistics!