i think you need to read around the forum about making sweet cider- if you bottle when it tastes good and it still contains a lot of sugar it is going to keep fermenting in the bottle and those bottles are going to stop being bottles and start being high velocity pointy glass crystals. if you wait until it's done fermenting it's going to be very dry. you will need to inactivate the yeast somehow (cold, heat, chemicals) either during fermentation, or after fermentation is done at which point you can sweeten with sugar or juice
also, do you have really enormous thumbs or a really tiny iphone??