Any iPad 1 owners out there?

I'm still using my trusty original iPad which I bought almost 3 years ago. Mainly used for note taking at university, viewing PDFs at work and web browsing. Its been REALLY buggy lately, with persistent app crashes (for both stock Apple apps and 3rd party apps), plus this gem:



For iPad 1 (or 2, 3, 4) owners - is this a common issue, and if so, have you guys got any quick fixes?