See below. Wonder how accurate it is in real life, and if you recommend it. It's $50-60 so does not brake the bank. Has wind direction too.
http://vaavud.com/product/vaavud-sleipnir/ The Vaavud wind meter turns your smartphone into a high-tech meteorological tool. It enables you to take accurate wind readings, at wind speeds from 2 – 40 m/s , with a precision of +/- 4%, AND measure the wind direction with a precision of +/- 4%. It comes with a practical neoprene bag so you can take it with you anywhere.Works with the following devices: iPhone 4, 4S, 5, 5C, 5S, 6, 6Plus – iPad 2, 3rd and 4th generation mini and Air – Samsung Galaxy S5, S4, S3, HTC One and Google Nexus 4 & 5 and Droid RAZR m
http://vaavud.com/product/vaavud-sleipnir/ The Vaavud wind meter turns your smartphone into a high-tech meteorological tool. It enables you to take accurate wind readings, at wind speeds from 2 – 40 m/s , with a precision of +/- 4%, AND measure the wind direction with a precision of +/- 4%. It comes with a practical neoprene bag so you can take it with you anywhere.Works with the following devices: iPhone 4, 4S, 5, 5C, 5S, 6, 6Plus – iPad 2, 3rd and 4th generation mini and Air – Samsung Galaxy S5, S4, S3, HTC One and Google Nexus 4 & 5 and Droid RAZR m