Ruler Green

Calibration just says "invalid input" for any integer or decimal number. 20mm on screen is 23.75mm on a ruler. Worthless.

DOWNLOADED 12 DIFFERENT RULER APPS, THIS ONE WON.... Easy, free, clear, no ads, calibration is fast, simple, & accurate. HIGHLY RECOMMENDED!

cannot change from CM to INCHES on NOTE 5

It says "20," but it means 30.

I set calibration at 30 attempt.. My calibration is 19.75. (Sony eXperia M C2005)

suggest to display inch & cm at the same screen & maybe add a pointer. ;-)

Very good

The semplist, the best.

It works. No permissions. 28k. Wrong size on my phone, but easy to calibrate. 5*

Perfect for Samsung Galaxy Note !!! In order to be accurate, need to calibrate for Samsung Galaxy Note as below: 21.9mm = 20mm Green Ruler (Just enter 21.9 and done...)

Works well on Samsung Galaxy S3. No calibration is required as it is correct from first launch, well done app developers.

Superb app with no ads and no privacy concerns. The only thing I would improve on is the interface. This app should be upgraded to a holo interface.

Ruler like it's supposed to be. No ads. No unnecessary crap. No problems with calibration (here)

Measurments not correct at all, doesnt actually change between inches and centimeters

Description is wrong.

A screen lock feature would be good.

haven't a clue on how to use it, no instructions on how to measure with an electronic ruler

I cannot find a menu button on my new Samsung Note5, so I can't change from centimeters to inches. However, on my Note3, it was a phenomenal app. I never had to calibrate it; it was always accurate!

On my new Lenovo phablet it doesn't need calibrating. Spot in out of the box. Thanks!

Cant access calibration on galaxy s5

cannot change from CM to INCHES on NOTE 5

Stopped allowing you in settings to do calibration or switch between inch and cm. Unistalled.

I set calibration at 30 attempt.. My calibration is 19.75. (Sony eXperia M C2005)

Spot on accurate on install on Nexus 5. No calibration needed!

One of the essential tools I always install

Small size and works well. Thanks.

Calibration does not work on S6. 8.4% too large. Says invalid input

The measurement is not right. Each cm is about 1.2 real cm.

Perfectly calibrated on Samsung fascinate

Best ruler on Market I've found!

A useful app which does what it says. On my galaxy note the correct calibration was 21.6, not 21.9 a others have suggested.

Very small app and it does what it says on the 'box' :)

can't calibrate it it comes up with a random calibration each time.. entered 18 and it displayed a message "invalid entry" so I did it again and it was way off.. did it again and this time too small Junk!

suggest to display inch & cm at the same screen & maybe add a pointer. ;-)

Very good

The semplist, the best.

The cliberation ask me to measure 20. But in fact I should measure 30 mm for the calibration.

DOWNLOADED 12 DIFFERENT RULER APPS, THIS ONE WON.... Easy, free, clear, no ads, calibration is fast, simple, & accurate. HIGHLY RECOMMENDED!

On my phone (Samsung Note II), it worked immediately. No ad's either! On my tablet, (Samsung GT-P6201), I had to calibrate, with a different factor than suggested. i.e. the 20mm on-screen measured 18.5. Entering 18.5 made the on-screen 20mm measure 30mm. The factor needed is 27.75 (18.5/20x30).

Does what it does very well.