Custom mobile plans are picking up interest and steam. The most recent company to launch a custom option is Sprint, which on Aug. 9 will roll out Virgin Mobile Custom for users. The aim is to give customers more flexibility in their prepaid options, with the ability to change as they go.

The move follows a number of smaller operators offering its customers customized mobile phone packages that give the user the option of adding more functionality or decreasing it from month to month without having to worry about service fees or simply the inability to change an existing two-year contract.

"The value proposition is pretty straightforward: allowing customers to create and customize their plans and be able to change them any time," said Dow Draper, the president of Sprint's prepaid division. Virgin Mobile is a Sprint subsidiary.

The idea is that a user can gauge their usage and decrease their prepaid package accordingly. Say one month you only sent and received around 200 text messages, but your plan allowed for up to 750 messages. That means the following month, a user could reduce the messages on offer to 250 total messages, which would reduce the monthly costs.

The new option, however, will not be available from any Sprint store. Instead, the company is going to initially rely on Wal-Mart for its custom plans. They will only be sold at Wal-Mart locations where Sprint has a strong network coverage and won't be available online.

"We're starting with Wal-Mart , but that doesn't mean things can't change in the future," Draper added.

The new move appears to be part of Sprint's overall effort to win over public support for its operations as it seeks to merge with T-Mobile in what the company has said would deliver more competition in the cell phone market in the United States as well as drive down prices.

Tech Times reported recently that SoftBank CEO Masayoshi Son, head of Sprint's parent company, believes the new move would benefit more Americans if approved by regulators.

"We can make it more effective by getting bigger scale," he said during the interview session with reporters. "Us becoming a more credible competitor in scale is something good for American consumers and citizens."

The new custom plans should help increase interest in the company as regulators delve into the merger proposition.