This is kind of on topic, but certainly related to the Op.
With the ELM have any of you had battery drain problems? as I have read so many conflicting stories about them, I think there is only one that turns off and it costs a bomb, the reason I ask is i fancy one of these apps, yet I often have times where my car will not be used for several days.
Any feedback would be good
The rest of the topic I read with interest which encourages me to add an app so to speak