The original iThoughts apps will no longer run on iOS11
Apple have removed support for 32bit apps on iOS11. The original iThoughts apps are all 32bit and so will not run.
Originally I had 2 apps, one for iPhone and one for iPad (blue and orange icon.) They were retired over 3 years ago and replaced with a new universal app - also called iThoughts (with an orange and white icon.) This is a completely updated version of the original apps - with many new features and designed specifically for iOS9/10/11 - see here.
Because it’s a new app, it’s also a new purchase (and whilst I'd love to support discounted upgrades - Apple don’t allow such a thing, so I'm unable to 'sweeten the pill' - sorry!)
There is a 'free trial' version (iThoughts2go) if you'd like to try it out (or just use it as a mind map reader app.)
Why didn't you tell me sooner?
Apple do not tell developers who has purchased the app. There is no way (for developers) to contact customers direct. In AppStore land, Apple are the 'resellers' and developers are just the 'manufacturer'.
Why just stop the app from running?
I haven't done anything. Apple have stopped older (32bit) apps from running on iOS11. This affects many tens of thousands of apps.
Why didn't you just update the original app?
There are a whole bunch of reasons (technical and bureaucratic) that I can try to explain if you want to contact me direct. This is not my preferred situation (nor yours!) but it's the least bad option available to me.
What about my maps?
If you've already upgraded to iOS11 then there is only 1 way to get your maps out the old app and that is to connect your device to a computer (PC or Mac) running iTunes and grab a backup using iTunes file sharing https://support.apple.com/en-gb/HT201301
Save the backups folder to your PC/Mac. In that folder will be a bunch of ZIP files. The one you want is probably the one with the most recent date/time.
You then need to get this ZIP file into the new iThoughts app. Easiest way is often to email it to yourself then tap on the ZIP attachment in the Mail app and choose 'Open In/Copy To iThoughts'. Another way is to place the ZIP file in Dropbox or iCloud Drive and then use the associated app on your iPhone/iPad to download the ZIP file - then use the usual Share -> Open In/Copy To iThoughts approach to transfer the file from Dropbox/iCloud over into iThoughts.
Any issues, just contact me direct.
I haven't updated to iOS11 yet
In that case, you have more options. You should get the latest app installed (even just the free iThoughts2go app) and then you have somewhere to transfer your maps to. Then follow the instructions here.