I have a few gift / store / reward cards that I use at some stores, simply for the free rewards - A free drink every now and again, 10% off, etc. One store I used to frequent for my caffeine fix switched from a magnetic stripe card to an app-only system, for mobile phones.

I figured this would be OK - one less card in my wallet, and I always have my phone with me. I registered the card, got my free drink, and left. They would scan my phone, just like at a few other retailers, to get my gift card number. A simple bar code, that’s all.

Then, I got a great idea!

I took a screen shot of my new bar code, and put it as my wall paper. Enough of it fit between my icons that the sensor picked it up! Remember, bar codes that look like a UPC label only need to read the lines across horizontally. I had a working prototype, and one less app on my phone now too!

What if I stacked a few bar codes? I opened the screen shots on my computer, and pasted the bar codes in between the 4 spaces where icons go, and tested it out. All 4 of them worked at their respective locations, and all I did was shrink the height on each one!

This will take some careful work, so I would suggest screen shots of each reward card that is on your phone, and using your computer for the editing. This will prevent scaling issues that may arise from editing on your phone (possibly). Open up each of the barcodes in a decent picture editing program (i.e. GIMP, Photoshop, etc), so that you get the highest quality of a picture back.

Create new layers for each bar code, so you can move them independently of each other. Add a label showing what that barcode is for, either just above or just below, and combine these two layers.

Next, line them up, with some space in between each reward card. Ensure you are staying in the same width and height constraint of your mobile device, and remember to have some blank space (black, brown, white, whatever colour) for the Dock area at the bottom, and the Status Bar area at the top - otherwise, you’ll see bad artifacting from the background image, depending on your phone model.

Finally, transfer it to your phone, and set as the wallpaper, or even the lock screen.


  • Less apps on the phone taking up space
  • Images are synced automatically anyways to my cloud (or Dropbox, or BT Sync, or OwnCloud, or OneDrive, or Box…)
  • As long as I don’t care about having a spare home screen, I can probably squish more bar codes on a single page
  • Bar codes won’t change over time, so this could be permanent
  • Because it’s also my lock screen wallpaper, I just need to remove the clock on the front, and my phone scans without unlocking!
  • You can print it out and the paper form works well too (until it gets ripped or ruined)


  • Can’t post a screen shot on here of my work - I don’t want everyone using my accounts
  • If it’s on the lock screen, anyone finding my phone will get all my bar codes (my lock screen blurs now, so not an issue)
  • People keep asking me how to do it when I show my “cool” screen (hence, this blog post)
  • No new offers from the apps come in automatically (only if you remove the app from your phone)

So, the pros outweigh the cons. It is keeping the world a little greener (not printing physical plastic cards anymore), and allows us to keep less cards in our already-thick wallets. If you find other tricks like this, feel free to share!