I often see people posting pictures of groups that look like the group and data were measured in some software. I assuming this is some app for iPhone or etc... anyone have a idea of what this is or a recommendation for an app to do this?

I use Sub MOA on iPad and its available as Range Buddy for android/ PC. Free and it works fine after a little learning curve.

I use On Target on a desk top, just need to scan target in.

Ballistic-X for your I-Phone. Simple and works extremely well.

+1
I believe On Target is what is used for official benchrest scoring.

49.95 for fully functional program. The others are free and work just fine for the average shooter.

I've never had the need for the pay functions in On Target.

You do understand trial software right? It quits functioning after 15 days unless you buy it.

I can only find reference to the Sweany device as approved by IBS and NBRSA. Could you provide a link in the rules for this as used in registered match.

I just use a good old-fashioned engineers scale in 1/10". Interpolate to the nearest 0.05".

There's a non-expiring shareware version out there. Or at least when it does expire, it still maintains base functionality.

I've been using it for over a dozen years on several computers.

Been shooting BR for many years and haven't heard the term sweany device. I still learn a little every day. This is what we use in BR.
http://www.neiljones.com/html/target_measuring.html

What you posted comes up when searching Sweany Device or Reticle. No matter as I still haven’t found where On Target Software or any Software is approved for scoring.

https://internationalbenchrest.com/documents/folder/rules/rulebook_for_score_and_group_disciplines
Page 21 section F
Group Measurements
1) Groups are to be measured by any method approved by the IBS in one thousands of an inch. The Sweany reticule rule or its equivalent will be the only official measuring device used at all registered matches. In measuring groups fired with calibers for the caliber to be measured, the measurement shall be made from the extreme outside edges of the two widest bullet holes and the actual differential of the larger calibers shall be subtracted from the measurement read on the Sweany Measuring Scale.
2) All scoring shall be by group size from center to center of the widest shots, using the Sweany Rule or equivalent. The following procedure has proven successful.

https://www.nbrsa.org/wp-content/uploads/2019/02/rule_book_nbrsa_201901311001.pages.pdf

I take it that this is the Sweany Reticle rule also.

Group Measurements: Groups shall be measured in .001 increments. The Host Club shall be responsible for providing a Dial Caliper which has scribed reticles of at least .224, .243 and .308. Other caliber reticles may be used if available. To measure groups shot with bullets of a caliber different from those above, the available reticle closest in size to the different caliber bullet shall be used and the difference shall be added or subtracted as appropriate.

All I will say is IBS and NBRSA uses the Neil Jones type measuring device. If that is a sweany, it is good, but whatever it is called, the Neil Jones device is used only by these 2 organizations for measuring groups.

I just downloaded Ballistic-X for $7.99 and used it on some target pictures I had on my phone. That’s pretty slick