I am sorry to hear that app, I think this underlines the importance of having good export/import functionality so your data does not get locked in a proprietary format. I am a little surprised the Surfulater author apparently created a new app (Clibu) with no way to import from Surfulater?
For what it's worth, I moved from Evernote to CintaNotes, which is a lot more bare-bones, but works well for many of the type of notes I keep. Besides that I keep a development log in markdown in plain text files.
-Jibz
CintaNotes was what I was going to suggest, but it doesn't keep rich format items, so I didn't.
I personally use
Ema Personal Wiki, as it works across all of my devices (sync via dropbox), is
OSS (so I can make any changes I want), and stores in plain text. I forked the repo so that I always have the version that I want, irrespective of any changes that he makes.
I'm also trying
Boostnote, but haven't gotten that deeply into it yet. It's also
OSS, but updated more regularly.