ProjectorPro 4+

Web page on Safari needs flash. They recommend the app for iOS phone & pad. Does not function at all on the iPad. Seems to work on the phone. I'll write an amendment from my phone.

I just purchased this app in full knowledge that it is not 64-bit ready and may soon become obsolete. I already knew that my recently discontinued projector was in their database.
The app is very well done, easy to use, with a great visualization of the projector to screen setup. Not to mention it comes from a highly respected forum in the AV community.
To be honest, why people complain about $2 for any reasonably functional app is beyond me. As far as I'm concerned, just my single use of this app is well worth the $1.99 purchase and I would have no problem paying for updates to the database. Putting things in perspective, a good app is certainly worth a lot more than a cup of coffee or a beer. As Stan Lee would say, "Nuff said!"

Two points: Have been using this app now for a few years. Have only run into a projector missing from their data base twice now. Both times I emailed the support address, provided the projector model number, and the missing projector was added very quickly. Like, within 24hrs.
The most important calculations are included in this app and they are reasonably accurate. This is esp. true of Foot Lamberts or the perceived intensity/brightens of a projected image, keystone, and image size vs. distance.
Price is reasonable and their update model seems fair - considering the tool remains free when accessed through a browser.