"We were screaming and jumping around when we first found out we'd made the top 33 amongst hundreds of promising teams globally," she said.
"It is overwhelming, but at the same time encouraging, and even more motivation for us to get back to work and do New Zealand proud. We're excited for what is to come."
The world finals will be held in Seattle next month where Tether will compete against 33 finalist teams from around the world for a US$50,000 ($70,200) prize and the opportunity to meet Microsoft chief executive Satya Nadella. Lei said the team would be spending the next month preparing for the finals.
"We've got a bit of time between now and Seattle to refine our pitch and prototype and we're trying to get a lot more sign ups on our website and people registering their interest, so we have more market validation to bring to the table," she said. "We want to arrive in Seattle with the product ready to go."
The team had already refined the Tether app a lot since its first development, and had been taking on board advice from Microsoft, who they had been working closely with, and from other businesses that had been offering to help.
Lei said the product was constantly evolving and the team hoped to have a fully refined product by the time they went to Seattle.
"We've approached a lot of different people and I know Kiwis are really great in terms of the fact that they are willing to give a lot of their time," she said.
"So we've taken that feedback and we're just trying to pitch our ideas really succinctly so people immediately get what we're doing. I think that's really been the most difficult part."
Lei said the team were looking forward to exploring Seattle but were most excited to try out Microsoft's new HoloLens - which the finalists would all get a chance to try out.
She said although they were nervous about the finals and needing to have Tether and their business plan perfected, they were also excited about the experience.
Last year's New Zealand team, Estimeet, won the Innovation category and US$50,000 as well as a trip to the UK to work alongside Microsoft developers, with their app Estimeet (now called Tomato) which uses geolocation software to track how far away friends were from a meeting point.
Following their UK trip, the team were accepted into the accelerator programme Lightning Lab.
They have just completed the three-month programme.
Lei said it was exciting to see how Estimeet had done.
"It's really inspiring that they've managed to go so far since competing in the Imagine Cup," she said. "It's exciting to think, maybe that could be us."
Microsoft Imagine Cup
• Global student technology competition.
• Competitors have to create a project using Microsoft software or Azure.
• Students 16 years and older can compete in teams of up to four.
• World finalists will compete in Seattle at the end of July.
• Contestants compete in three categories - innovation, world citizenship and games.
