You know...look around the App Store. Some apps are available as + meaning one purchase works on all your modern iDevices. Then their are apps (and developers) who create unique versions for each screen size, charging for each, and even adding in-app purchases for customization.
OK, Im not selling software to make a living, and Im no Bill Gates but HanDBase on iDevices has fallen into the latter definition app types.
Heres my advice...if you have an iPhone or iPod touch, buy it here, including the forms creator in-app purchase if you need that functionality. Next, get a Retina-enabled iPad and use your files in 2X mode. Works just fine and renders fine. In fact, the minimalist if layout of the smaller iDevice screen on the iPad actually makes it a program youll use rather than fiddle with, and get lost in, screen art.
Also, since this developer, around since the dawn of Palm Pilot hasnt at this point integrated iCloud, DropBox, or any other cloud-based personal syncing, your only options are (1) forget my earlier advice and get another modern database app, (2) email your databases back and forth between your devices, loading each time on the receiving device, after deleting the same file older but still present on the receiving device, or (3) live cabled to iTunes and save/copy daily your updates on the App tab.
So my two stars would be one if I didnt have such a long experience with this app ... I can work somewhat efficiently with these short-comings. But be known...Im always looking for the next solution (not FileMaker/Bento commercial bloatware either!).
P.S. Are you ever gonna change the stinkin flipping page effect when navigating through records. Weve all graduated from PowerPoint transitions and animation. We want speed, not glitzy graphical elements.