Polygonium released Flexy Drums, a free way to practice your finger drumming. If you'd like to export your drumming to MIDI there is an option do so with if you grab the $1 Pro Version In-app Purchase.
Flexy Drums iTunes Description:No Ads!
Sick of drums which are too small or in wrong place for your fingers? Flexy Drums is the best mobile drums you have been looking for. Customize the position and scale of each drum part for your finger drumming needs. Play, record and enjoy improving your skills without any disturbing Ads. Flexy Drums is a free app but some in-app features such as Save, Load and Export to MIDI will require payment.
◉ Innovative design
◉ Customize positions
◉ Customize scales
◉ Save & Load
◉ Export to MIDI
◉ Play over musics or backing tracks