https://www.google.co.uk/amp/themarketmogul.com/brexit-mean-developing-world/amp/
"the EU are currently negotiating new deals with a large proportion of the developing world. If Brexit were to occur, therefore, it is highly possible that the UK will not be involved in these new trade deals. Clearly, a non-EU incorporated UK would seek to write their deals with these developing nations, particularly those that take part in a large amount of trade with the UK, but this would undoubtedly take time. It is unlikely that the developing world would seek to impose trade barriers but the uncertainty created could prevent investment, and have indirect effects harming developing nations."
€960bn over six years in development aid from the EU. Do you really think the Daily Mail will be rooting for the UK to pay a similar share when we're out? - they already resent the 0.7% of GDP on aid. Will you be rooting for it? (Not of course that it was a promise to spend our EU contributions on the NHS, but I really don't think many who voted leave will campaign for what we "save" to go on overseas aid. There was certainly no bus.)