There was, is and most likely never will be any way to run Flash on iOS. Apple argued, Flash has too many performance problems, which is even more important on mobile devices with limited resources and battery. Until this day Adobe hasn't come up with a version of Flash which runs acceptable on mobile devices where it can be installed, like those running Android.
Even if Flash could be installed on iOS or if you would get an Android tablet, there is no guarantee you're able to use the Flash apps you want to use. All of them would have to be rewritten by the developer to support touch input. But Adobe has abandoned Flash for mobile devices at the end of last year which makes it essentially a dead-end technology. So, I don't think any Flash developer will rewrite their apps to support touch input.
Your best bet is to look for alternatives of the Flash apps you've used, there are excellent accounting apps in the App Store.