TennisTension app for iPhone and iPad

• TennisTension is the FIRST WORKING mobile app that instantly measures the momentous string tension of a tennis racquet with extreme consistency and accuracy. We, the developers, GUARANTEE full satisfaction if you trust and buy TennisTension. The error of the measurements is less than 0.2 kg. Tracks the TENSION LOSS. It records and analyzes the ringing sound heard from the strings when they are hit with a stiff object (pen, pencil, another racquet, fingernails etc.).
• Systematically tested with different racquets and strings by players at different level of play - from beginners to ATP professionals.
• At ATP Sofia 2019 in January, 3 from the seeded players tested, approved and gave recommendations for improvements, which we implemented: string pattern, hybrid stringing, string opening size influence, noise disruptions.
• If the user defines accurately all parameters of the tennis racquet and its string, then the error of the measurements will be less than 0.2 kg.
• Parameters to preset: head size; string pattern; main and cross string thicknesses and types; string opening size; stringing type. If some of them are not defined, the app will use the average default values or the last values the user put.

Use the "Calibration" to cope COMPLETELY with all specific characteristics of every racquet, string and stringing machine/stringer combination.

Instructions for use

- The user has to learn how to produce the proper ringing sound close (2 to 10 cm) and in front of the phone microphone. Find the microphone which uses single, very small hole either at the top or at the bottom of the phone.
- Remove the dampener - if you have.
- Tap the racquet string very gently several times every 1 or 2 sec. with a stiff object. The best way is with pen or pencil, or use another racquet, fingernails, etc.
- While ringing, the resonating racquet string must stay 2 to 10 cm from the microphone, in front of it, especially in a noisier environment.
- To receive the exact momentous string tension, define all the necessary racquet and string parameters. If you dont know some of the them, default average values are taken for the calculations, or the last values that the user put it in.
- TennisTension measures the average tension between main and cross strings of the racquet (for example, if a racquet is strung 25/24 kg, the measurement result will be 24.5 kg).
- String tensions of hybrid strings could be measured as well.
- The error of the measurement result is less than 0.2 kg.
- Calibration is provided, though it is not necessary to make it.