A photo project by the IRC, called What's in my bag, documents what possessions refugees and migrants have brought with them. Many of them had brought smartphones, chargers, as well as spare cell phones, emphasising the importance of keeping in touch.
Donohoe said many refugees use free messaging services, specifically WhatsApp, Facebook and Viber, to communicate with other refugees and family members who have been left behind. Some even take selfies to let their family know they have reached Europe safely.
IRC is the main responder on the Greek island of Lesbos, where up to 4,000 people are arriving each day, according to Donohoe. GPS, a common function of most smartphones, has proven vital to many refugees.
"(GPS) prepares it for when they wanted to cross the border town along the Greek side across to Macedonia," explained Donohoe. "GPS allows them to do that."
Donohoe also met a Syrian refugee whose boat sank as he crossed the straights from Turkey to Lesbos. He used WhatsApp to alert the Greek coastguards, and used his phone's GPS to make sure he swam in the right direction towards the island.
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Kate Coyer is the director of the Civil Society and Technology Project at the Central European University. She has been helping refugees in Hungary by creating wi-fi hotspots which allow them to connect to the internet. She emphasised how important phones have become to refugees.
"The majority of refugees are traveling with mobile phones, or at least one amongst families or groups traveling together" she told CNBC via email. However, she added that many do not have phones, which limits their access to important information.
"It is a vital tool and for people who have taken so little with them from their homes, and lost most of what they had along the way, their phones are among their most valued possessions."
Phones not only allow refugees to keep in touch with their families, but also to share crucial information about prices, traffickers or how to travel safely through Europe.
"They are also using GPS navigation tools, Google maps, online translators, currency exchanges," added Coyer. "There is anecdotal evidence to suggest the power of these online tools could help bring down some of the costs and dangers of trafficking. It wouldn't eliminate traffickers, but it can help refugees from being taken advantage of to the nasty extent that they are now."
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Keeping in touch online is proving vital for families who have become separated. The Red Cross has set up a website called Trace the Face where migrants or their families can upload pictures to help them reconnect.