Our church does small groups on Sunday nights, and I have a preteen group and an elementary group at the building. This time with our preteens is an extended time (90 minutes) and is much more informal than our Sunday mornings. We also have most of the building available to us.
For my first trial, I used three, old iphones who's owners had upgraded and were able to keep their old phones. After getting into groups, I challenged my students to go out into the church building and take photos of places were people could serve and sent them off with their phone. The exercise made them think of all the ways they could serve around the building. You also get some funny pictures along the way.

For my second attempt, I wanted to do a scavenger hunt like activity using QR codes that phones and tablets could scan and be redirected to web pages. This activity turned out to be a bit more involved than I thought and I almost didn't get it finished before our evening class. To do this the way I did, I need to create a simple website, generate qr codes for each page, print the codes and then hide them around the church building. Yes, it was a lot of work.
I knew I wanted two groups, so I created five simple web pages for each team. I use Adobe Muse to create websites, so it was pretty easy. I had three pages of content and a start page and end page. Each content page contained a section of scripture that went with our lesson series and each also had a question from the listed scripture. The text of the question was a link. Students typed in the answer and if correct, they were given a hint to where the next code was hidden. I created the QR codes using a free online QR Code generator found on google search.


I created a card with a QR code for each team with a hint to where the first challenge code was hidden. This card they got in the classroom to get started. Then they were off. I placed one code in the wrong order for one team, but was able to get them back on track. The kids had a blast, and back in the room afterwards they were able to talk about the scripture and answers from the activity. One issue we found was there are lots of dead spots in our building with no wifi, so they had to come back to a central area to get the websites to load once they scanned the codes.
So my take aways: Kids love using technology; they do retain some of what they do, but boy is it a lot of work. You'll definitely want to start well in advance. I'm thinking my next trial will be again with QR Codes, but linked to a map or possible a Bible video on a lesson hand out. Another possibility would be prayer stations where they access content as they move around each station.