Cinkerator:
There are sensors out there but they are way to costly for what I want to do.
You can get a suitable temp sensor for about $5. A pressure sensor may cost a little more.
For reasons I don't understand, it can cost about $100 to put an Arduino on WifI. If you can avoid doing that, the whole deal could cost less than $50
If your phone can see anything of note here
it is looking at the output from an Arduino