Sensor data over bluetooth

I am currently undertaking a project that will produce readings. it is just a proof of concept so i am using an LDR to make a light sensor. i was wondering if anyone would know how to send the data along with the time to an android device so that it can be easily turned into a graph. I have found apps which can do this in real time, and managed to get them to sort, but for my project i would like to store the data and maybe export it so it can be easily turned into a graph similar to how Excel would do it .

Also i have started to use MIT inventor to make an app for this but am struggling to find the resources for this purpose

Thank you in advance,

The procedure for sending data over Bluetooth is exactly the same as it is for sending it to the serial monitor.

Serial.print(data);

Most bluetooth terminal programmes can record the data to a local logfile. If you prefer to record on Arduino, which makes more sense for longer term operations, the DumpFile example in the SD section of the IDE is all you need. You simply send the filename from the phone. A single character trigger may suffice.

Unless you specifically want the time for other purposes, there is no need to record or send it, you just need to record at regular intervals and Excel will do the rest.

App Inventor is really good way to waste time re-inventing the wheel, but check to see what is already available first.