Smartphone Apps For Stamp Collecting

For those who have stamp apps for their smartphone, what do you use?

Since I use excel for inventory, I am going to try that but creating a special view through a formulas or pivot tables.

I had looked at one time for some app(s) for stamp collecting. No luck on anything particularly useful.

I guess not many people using their smart phones.

I will likely just use my excel file and use it. I can use OneNote but I want something that does not need wifi to use.

I keep my want list in a Google spreadsheet so I can pull it up from my phone, iPad, or any device with internet access. And I can email the link to dealers, if I want. Otherwise that's about the extent of it for me.

The gang on the podcast Stamp Show Here Today reviewed smartphone stamp apps in episode #31, published May 24, 2015. The only app worth noting is for collectors of US stamps dated 1847-1947. United States Stamp Catalog for Android os. I think an inventory app would be amazing! Maybe you can search around on Product Hunt. I would love to see HipStamp develop something. Just seems like the average demographic of collector is not using a smartphone. Sounds like use of Scott numbers is a major barrier and the app Scott has published is pretty bad and expensive. Hopefully others can weigh in if we are missing anything?

Stamp Show Here Today - The Postage Stamp Collecting Podcast: 31 - World's Fairs, Expos, and Stamps and Stamp Collecting
https://overcast.fm/+Dl0x52vF8/04:38

The USPS also sells an app but have not used them. I wanted something with local storage to be able to use disconnected.