There was an update for Runtastic Pro yesterday, but its still not working.. That was just wishful thinking anyway. I personally like the activity rings, and so far the only app that adds to the rings is the built in workout app.
HOWEVER, the stats are very off in my opinion. If i cycle, and take my phone with me, its fairly accurate.. As in matches my bike computer on calories... however the mileage varies from day to day... Not by a lot, but say i do a ten mile cycle... 10mile accurate, by using the circumference of my wheel and bike computer... one day on my watch it'll say 10.2 and another 9.88. Route being the exact same every day. Now that may not seem like a lot of difference, but it hugely affects the average speed. 1 or 2mph is a big deal to a cyclist, who's trying his hardest to ride above a certain pace.
Also i wish they'd add levels at which you worked out at... For example an elliptical workout. If i really push myself my HR staying about 160 average, (peaking at 190) the calorie count is less than 300 for a 30min workout, whereas the machine that actually measures wattage is around 450. I'm sure if i went for a light option it would probably say 300 also... so is it really taking in the HR to consideration ?
I'm fairly certain its not, cos if i cycle, without my phone... the calorie count varies tremendously also. Why though? Surely it should be smart enough via the HR going hard for 30mins... but it doesn't. It just takes 30mins of excerise as 300 odd calories.
If you're weight training and choose other as the option, then forget it !!! it says your HR is in the low 60's.. but if you wear an actual HR monitor its much much higher than that.. 140's as an example.
So to sum up my rant... The watch is okish at best as an exercise device.. Really you're best off using a proper HR chest strap and a dedicated app.. and forgetting about the rings.