Smart BP HR SPO2 Bracelet M2S Smart Band Heart Rate Blood Pressure Pulse Meter Bracelet Fitness Watch Smartband for iOS Android (Blue)

This is the sixth kind-of watch that I have tried covering various brands, and "THIS M2S" is by far the best... I installed and used the Wearfit2.0 app and had no troubles with it... I am using a Samsung S5... I have used the older version Wearfit on a previous generation watch, and I find the newer version when it comes to the Bluetooth locking and staying lock significantly much better... I would give this watch a 5 Star rating, but I have a slight accuracy issue with the SPO2 readings only, that appear presently 4 point higher compare to a finger SPO2 device I have... Now the most significant aspect is that the watch holds all the data until you link to the phone to sync all data collected, which this watch does nicely... Option Rule: Just remember to leave data on Watch and not on Phone when setting it up... Doing this will keep all the data on the phone ultimately, but allows 24 hour shots of data from watch to transferred to the phone when you are ready to do it... Other watches are often required one to maintain BT connection all the time usually develop signaling troubles which harms data collecting process as one moves during sleep... Doing this down load many times now has given me data on the Hour that I was truly seeking, that is reliable... And it does this with BT off during data collecting times, and that saves battery... So... This unit also has good batter life... So, I would say so far,,, I am seeing 4 to 5 days running times on this small battery's in side of this watch... Thanks!