Good news! In new Android Amiga Emulator from Google Play I'm now playing "Pinball Dreams" in full! Just download "Uae4arm" and in emulator's settings tick "Custom Control", on "Port0" and "Port1" select "Nubs as mouse". Far left select "OnScreen" option. You will see that numbs are marked as letters X, Y, R etc....
Go back on the input screen. Provided that you already ticked options "Enable mousehack" and a "Custom Control" now in drop down lists for 'L' select "Arrow down", for "B" select "Left Amiga Key", for R select 'Right Amiga key', for down select "Arrow Down"
Actually you are now enabled virtual joy pad buttons on the right: one button for spring a ball and two the others for left and right pipe...
*EDIT
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Not just save states works perfectly but you can even position dedicated buttons for pinball dreams (or any game) at the part of the screen where is the most convenient for you... *tip: when reposition dedicated buttons on the screen do that by touching a micro-mini taskbars of mentioned buttons or they wouldn't move from a seemingly fixed place...
*EDIT 2
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Of course, configurations allows one to save specific order of floating virtual joypad buttons for specific games as a specific configurations.
PS: Exactly 2.5 years of hopelles waiting and relieving on the end...