How about sending text messages on mobile phones for free?

Parents can use the SMS function of China Mobile 139 mailbox. After logging in to 139 mailbox, click "SMS" under other featured applications on the left menu to use it, as shown below. For this short message function, different provinces will give away a certain number of free short messages (limited to sending mobile phone numbers) according to the current activities, which is subject to the warm reminder at the bottom of the self-written short message sending page when you log in to 139 mailbox. If the number of messages given exceeds 0. 1 yuan/piece, a fee will be charged. However, sending self-written short messages to Unicom and telecom numbers will be charged according to local tariffs and will not be included in the number of gifts.