I'd like to be able to check if certain strings exist within my app, in either the "designer" or the "blocks" view.
Any attempt to search for how to do this gives results that are for handling strings using one's app. I wasn't even sure how to phrase the subject line of this post to convey what I need. I tried doing a UNIX "strings" command on the dot-aia or dot-apk files, with no luck (strings I used in my app did not show up in the "strings" stdout). Using the "find" command, within whatever browser one is using to run App Inventor, sort of works, but it's hard to tell what the results are for sure.
See if the string is IN the app, that is, if I look at the designer or blocks view in my browser, the string is literally there in the various components I've placed. I guess what you mean by "when designing the app".
You could always download your project to an aia file, open this up, and find the bky and/or scm files. Carry out text search on these files should return your string locations....